Txoj Cai Ua Haujlwm ntawm Hloov Hom Fais Fab
Cov txheej txheem ua haujlwm ntawm lub zog hloov hluav taws xob yog qhov yooj yim to taub. Nyob rau hauv linear fais fab mov, lub hwj chim transistor yog ua nyob rau hauv linear hom. Tsis zoo li cov khoom siv hluav taws xob tawm, PWM hloov hluav taws xob ua haujlwm lub zog hluav taws xob nyob rau hauv thiab tawm hauv xeev. Hauv ob lub xeev no, cov khoom siv hluav taws xob ampere siv rau lub hwj chim transistor yog me me (tsis tshua muaj hluav taws xob thiab siab tam sim no thaum ua haujlwm; siab voltage thiab qis tam sim no thaum tig tawm) / volt ampere khoom ntawm lub hwj chim ntaus ntawv yog qhov poob generated ntawm lub khoom siv hluav taws xob semiconductor. Piv nrog rau cov khoom siv hluav taws xob tawm, cov txheej txheem ua haujlwm tau zoo dua ntawm PWM hloov cov khoom siv hluav taws xob tau ua tiav los ntawm "txiav", uas txhais tau hais tias chopping cov input DC voltage rau hauv cov mem tes voltage nrog lub amplitude sib npaug ntawm cov input voltage amplitude. Lub luag haujlwm lub voj voog ntawm cov mem tes yog hloov kho los ntawm tus maub los ntawm lub zog hloov hluav taws xob. Thaum cov input voltage raug txiav mus rau hauv AC square nthwv dej, nws amplitude yuav nce los yog txo los ntawm ib tug transformer. Los ntawm kev nce tus naj npawb ntawm cov windings theem nrab ntawm lub transformer, tus naj npawb ntawm cov zis voltage pawg tuaj yeem nce ntxiv. Thaum kawg, cov AC waveforms no tau kho thiab lim kom tau txais DC tso zis voltage. Lub hom phiaj tseem ceeb ntawm tus maub los yog tswj kom ruaj khov cov zis hluav taws xob, thiab nws cov txheej txheem ua haujlwm zoo ib yam li tus tswj cov kab hluav taws xob. Qhov ntawd yog hais tias, cov haujlwm ua haujlwm, kev siv hluav taws xob, thiab qhov yuam kev amplifier ntawm tus maub los tuaj yeem tsim kom zoo ib yam li cov neeg tswj hwm kab. Lawv qhov sib txawv yog nyob rau hauv tias qhov tso zis (qhov yuam kev voltage) ntawm qhov yuam kev amplifier yuav tsum mus los ntawm qhov voltage / mem tes dav hloov pauv chav ua ntej tsav lub zog transistor. Hloov cov khoom siv hluav taws xob muaj ob txoj haujlwm tseem ceeb: kev hloov pauv mus rau pem hauv ntej thiab txhawb kev hloov pauv. Txawm hais tias muaj qhov sib txawv me ntsis hauv kev npaj ntawm lawv qhov chaw sib txawv, cov txheej txheem ua haujlwm sib txawv heev, thiab txhua tus muaj nws tus kheej zoo hauv cov xwm txheej tshwj xeeb.
